Vehicle having a swivel wheel

ABSTRACT

A tricycle may be operable between a first mode of operation steerable by a tricycle rider, and a second mode of operation steerable by an individual pushing the tricycle. A rider handle, in the first mode, may be rotationally coupled with the stem in a manner permitting a tricycle rider to exert forces on the rider handle and thereby turn the fork, and the rider handle in the second mode, may be rotationally uncoupled from the stem, preventing forces on the rider handle from turning the fork. At least one rotation restrictor may be included for preventing the front wheel from turning to a position where the front wheel axis leads the stem axis, and for maintaining the front wheel axis in a position trailing the stem axis in the first mode and in the second mode.

TECHNICAL FIELD

The invention generally relates to the field of riding vehicles.

BACKGROUND

Whether used for transportation or recreation, tricycles may be used forriders of different sizes and capabilities. Some tricycles areconfigured to be propelled and steered by the rider. In some instances,tricycles are configured to be pushed from behind, by an individual,such as an adult pushing a child. Typically, when the tricycle ispropelled by the rider, the rider uses the pedals attached to the frontwheel and steers the tricycle using a handle which is typicallyconnected to the front wheel. Tricycles configured to be pushed frombehind sometimes include a mechanical steering mechanism to permit anadult walking behind the tricycle to mechanically turn the front wheel.

SUMMARY

An exemplary embodiment of the invention may include a tricycle operablebetween a first mode of operation steerable by a tricycle rider, and asecond mode of operation steerable by an individual pushing thetricycle. In both such first and second modes, an orientation of thefront wheel may remain unchanged regardless of mode of operation. Thatis, the wheel axis need not necessarily be locked in a position leadingthe fork axis when the tricycle is in the first mode.

More specifically, a tricycle may include a fork having at least oneblade configured to support a front wheel in a manner permitting thefront wheel to rotate about a front wheel axis. A stem may extend fromthe fork, and a handle may be configured to turn the fork around a stemaxis transverse to the front wheel axis. The handle, in the first mode,may be rotationally coupled with the stem in a manner permitting atricycle rider to exert forces on the handle and thereby turn the fork.In a second mode, the handle may be rotationally uncoupled from thestem, preventing forces on the handle from turning the fork. A rotationrestrictor may prevent the front wheel from turning to a position wherethe wheel axis leads the fork axis, and for maintaining the wheel axisin a position trailing the fork axis both when the handle is in thefirst mode and when the handle is in the second mode.

In one exemplary embodiment, the rotation restrictor is configured topermit the front wheel to turn less than 180 degrees (and in anotherexemplary embodiment less than 100 degrees), while maintaining the frontwheel in a position such that the wheel axis trails the fork axis.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a side view of a tricycle, without parental handle, and whichmay be used in a first mode of operation, according to an embodiment ofthe invention.

FIG. 2 is a side view of a tricycle, having a parental handle, which maybe used in a second mode of operation, according to an embodiment of theinvention.

FIG. 3 is front view of the tricycle of FIG. 2.

FIG. 4 a is a side view of a front wheel fork and stem assemblyconsistent with an embodiment of the invention.

FIG. 4 b is a perspective view of the front wheel assembly of FIG. 4 awith mud guard added.

FIG. 5 a is a front view of a handle assembly consistent with anembodiment of the invention.

FIG. 5 b is a cross-sectional front view of a coupling assemblyconsistent with an embodiment of the invention.

FIG. 5 c is a perspective assembly view of a stem and coupling memberconsistent with an embodiment of the invention.

FIG. 6 is a cross sectional side view of a coupling member consistentwith an embodiment of the invention.

FIG. 7 is a cross-sectional side view of a coupling assembly consistentwith an embodiment of the invention.

FIG. 8 is a cross-sectional side view of another coupling assemblyconsistent with an embodiment of the invention.

FIG. 9 a is a cross-sectional side view of yet another coupling assemblyin an uncoupled position, consistent with an embodiment of theinvention.

FIG. 9 b is a cross-sectional side view of the coupling assembly of FIG.9 a in a coupled position;

FIG. 10 is a perspective view of a holding mechanism, according to oneembodiment of the invention.

FIG. 11 is a perspective bottom view of the frame head tube consistentwith an embodiment of the invention.

FIG. 12 is a top view of a mud guard, consistent with an embodiment ofthe invention.

DETAILED DESCRIPTION

The terms of “front”, “rear”, “down”, “up”, “bottom”, “upper”,“horizontal”, “vertical”, “right”, “left” or any reference to sides ordirections are used throughout the description for the sake of brevityalone and are relative terms only and not intended to require aparticular component orientation.

Embodiments of the invention may include a tricycle operable between afirst mode of operation steerable by a tricycle rider, and a second modeof operation steerable by an individual pushing the tricycle. Atricycle, as used herein, includes any vehicle with a wheel in the frontand two wheels in the rear. FIG. 1, for example, illustrates is a sideview of a tricycle, and which can be used in a first mode of operationwhere a rider may propel the tricycle using pedals 141 and 142 (see FIG.3). A second mode of operation may be accomplished when an individualbehind the tricycle, pushes the tricycle using, for example, parentalhandle 500, as illustrated in FIG. 2.

Embodiments of the invention may include a tricycle having a frame and apair of rear wheels for rotatable connection to the frame. Asillustrated in FIG. 1, exemplary tricycle 800 may include a main frame700 including head tube 707. Two rear wheels 400 (see FIG. 3) may besupported toward the rear of the main frame 700. The main frame 700 maybe made of any material or have any structure, shape, or configurationcapable of supporting a tricycle rider. For example, main frame 700 mayinclude metal tubing or any other rigid material, and may be configuredto support a seat 600.

In one embodiment, the rear wheels 400 may be rotatably supported on acentral axle (the support shaft 702 of which is illustrated in FIG. 3)which may be inserted into the rear part of the main frame 700,effectively allowing the rear wheels 400 to rotate frontwards orbackwards. A seat 600 may be connected, by any known method, to the mainframe 700. The seat may have any configuration capable of supporting arider. It may include or omit a back rest, may be integrally formed orformed of multiple materials, and/or may be uncovered or covered incloth, fabric, or other material.

The main frame 700 may also have a number of connection options for seat600, effectively allowing the placing/adjustment of seat 600 at a numberof locations along the main frame 700. In one embodiment, a basket 410may be added and placed on the rear part of main frame 700 between therear wheels 400.

FIG. 2 is similar to FIG. 1, adding a parental handle, which may bepermanent, semi-permanent (e.g., removable with tools), or designed tobe removable at will. The term “parental handle” as used herein,includes any structure, regardless of shape or material that may begrasped by an individual behind a tricycle and used to propel thetricycle from behind. By way of example, parental handle 500 illustratedin FIG. 2, may be made of one or more metal pipes or from any otherrigid material. In one embodiment, the parental handle 500 may betelescopically adjustable to accommodate the height of the individualpushing the tricycle 810. The adjustable height mechanism of parentalhandle 500 may belong to any of the known adjusting techniques such asby a popup pin held within the inner pipe of the handle and which popsout of one of the holes of the outer pipe, where the pin may be pushedfrom one hole and popped out of a different hole, for adjusting theheight of the handle.

Embodiments of the invention may also include a front wheel havingopposing sides and a front wheel axis. For example, and as illustratedin FIG. 3, front wheel 100 includes first side 102 and opposing secondside 104. The wheel 100, as illustrated in FIG. 4 b, includes a centralaxis c at its midpoint 303, about which the wheel 100 is rotatable.

Similarly, embodiments of the invention may include a pair of pedals,each pedal configured to rotate the front wheel. Numerous types of pedalmay be employed constant with embodiments of the invention. Such pedalsmay include fixed pedals, removable pedals, foldable pedals, or pedalsthat flip up, retract, or have an otherwise alterable configuration.Thus, as used herein, the term pedal refers to any structure thatpermits a rider to propel a tricycle using foot power. An example ofpedals, consistent with embodiments of the invention, include pedals 141and 142 (see, e.g., FIG. 3). In addition, a pedal may be configured torotate the front wheel a portion of the time (e.g., during the firstmode when the rider propels the tricycle, and may be removable from,disengagable from, folded onto, or otherwise deactivatable during asecond portion of the time (e.g., during the second mode when a parentpushes the tricycle from behind).

Each of pedals 141 and 142 may be connected to the center of the frontwheel 100, via pedal rod 140. The pedal rod may be continuous andconnected to both pedals, or the pedal rod 140 may be configured of twoindependent sections, each connected to a separate one of the pedals 141and 142. In a first mode of operation, the propelling factor of pedalrod 140 may be connected, by any mechanical interconnection means, to arotating factor of the front wheel 100, thereby allowing rotation of thefront wheel 100 using pedal rod 140. By rotating the pedal rod 140, thefront wheel 100 may be rotated about its center axis, i.e. about themiddle part of pedal rod 140 which may act as the front wheel 100 axle.Alternatively, the wheel may have a separate axle to which one or a pairof pedal rods connect.

Pedal rod 140 may include three parts; a middle part located at a centerof the wheel 100 and used, among others, as an axle of wheel 100, a leftside for connection to a left pedal, and a right side for connection toa right pedal 141.

Embodiments of the invention may include at least one blade configuredto support the front wheel in a manner permitting the front wheel torotate about the front wheel axis. As used herein, the term “blade”includes any structure capable of supporting the front wheel in arotatable manner. A wheel may be supported, for example, on a singleblade or on a pair of blades. FIG. 1 illustrates an example of a blade130 used to rotatably support wheel 100. FIG. 3 illustrates wheel 100supported by a pair of blades 130 and 131. When a pair of blades areemployed, they are typically interconnected at upper ends oppositepoints at which they interconnect to the wheel axis and are collectivelyreferred to as a fork (although, as used herein, the term fork may alsoinclude structures that have just one blade.) Thus, in various figures,a fork is generally designated with the reference numeral 130. The forkmay be formed of individual blades that curve toward each other, or,interconnecting structure may join two individual fork blades.

The middle part of pedal rod 140 may be pivotally held by the opposingdistal ends of fork blades 130 and 131 in a manner such that the frontwheel is capable of rotating about its center axis. A mud guard 301 maybe disposed near a top of the fork 133, opposite distal ends supportingthe wheel.

Embodiments of the invention may also include a stem extending from thefork and being rotatably connectable to the frame. A stem may be anystructure connected to the fork and that is capable of conveying aturning force to the fork and/or that supports the fork in a rotatablemanner. For example, FIG. 4 a illustrates stem 305 that extends fromfork 133. Thus, when either the fork 133 or the stem 305 rotates, theother may rotate with it. The stem may be rotatably connected to theframe 700 via the frame's head tube 707. The frame's head tube 707 maybe a part of the frame 700, wielded to frame 700, or connected to frame700 by any other means such as screws.

In some exemplary embodiments, it may be beneficial to employ a stemgeometry that facilitates dual mode operation. For example, the width ofthe front wheel may be at least three times greater than the minimumdiameter of the fork's stem. This configuration can lower turningfriction, facilitating control from behind during the second mode ofoperation. In another embodiment, the stem may include a steel tube thathas a minimum diameter that is at least four times smaller than a widthof the front wheel. The stem may be comprised of sections having varyingdiameters. In the above examples, a smallest or “minimum” diameter maybe of particular interest, especially if that minimum diameter is at arotational stem connection.

For example, when the front wheel is in a range of 25 to 51 mm, the stemmay have a minimum diameter of 6 to 11 mm. For example, when the frontwheel is in a range of 45 to 55 mm, the stem may have a minimum diameterof 9 to 11 mm. For example, when the front wheel is in a range of 20 to60 mm, the stem may have a minimum diameter of 4 to 15 mm.

The stem's minimum diameter may be greater than one third the width ofthe front wheel, and the invention, in its broadest sense is not limitedto any particular dimension.

Regardless of the dimensions of the stem, it may be held by a bearingwhich may reduce turning friction and facilitate the second modeoperation and the first mode of operation as well.

As illustrated, for example in FIG. 4 a, stem 305 may have a centralaxis a, and fork 133 may have a fork axis b and the stem 305 may beconnected to the fork 133 in a manner such that the central axes a and bform an obtuse angle x therebetween. Angle x may be, for example, equalto or less than about 179° degrees. In some embodiments, angle x may bebetween about 170°-174°. In another embodiment the angle x may bebetween about 165°-179°. In a further embodiment the angle x may bebetween about 165°-173°. In yet another embodiment, the angle x may bebetween about 170°-175°. As the angle x approaches 180°, an ability tocontrol steering from behind in the second mode of operation may befacilitated by a minimum stem diameter of three to four times smallerthan the width of the front wheel. Thus, when the angle x is between165°-179°, a stem with a minimum diameter of three to four times smallerthan a width of the front wheel may be desirable. For example, asillustrated in FIG. 4 b, width w of front wheel 100 may be at leastthree to four times greater than minimum diameter d of stem 305. Forexample, when the front wheel width w is in a range of 25 to 51 mm, thestem may have a minimum diameter d of 6 to 12 mm. For example, when thefront wheel width w is in a range of 45 to 55 mm, the stem may have aminimum diameter d of 9 to 11 mm. For example, when the front wheelwidth w is in a range of 20 to 60 mm, the stem may have a minimumdiameter d of 4 to 15 mm.

Also as illustrated in FIG. 4 b, the central axis a of stem 305 extendstransverse to and is offset from rotational axis c of front wheel 100 bya distance y. In one embodiment, the minimal distance y may be no morethan about 50 mm. In another embodiment, the offset distance y is in therange of between about 18 mm and 25 mm. In yet another embodiment,offset distance y is in a range of about 15 mm and 40 mm. As the offsetdistance decreases with all else equal, so to decreases an ability toturn the tricycle from behind using parental handle 500. Thus, in oneembodiment, when the offset distance is between 15 mm and 22 mm, theangle x between the stem and the fork is between about 7 and 10 degrees,and the minimum diameter d of the stem 305 is at least three times lessthan the width w of the front wheel. This combination of geometries isexemplary of a configuration that may permit the tricycle rider to steerin the first mode and a parent to steer in the second mode, even when,in both instances, the stem axis a leads the wheel axis c, as will bediscussed later in greater detail.

In one embodiment the fork axis a is designed to lead the front wheelaxis c regardless of whether the tricycle is in the first mode of ridersteering control or the second mode of parental steering control. Theleading stem axis in such instances positions the pedals furtherrearward than they would ordinarily be if the stem axis a trailed thewheel axis c, potentially giving rise to a concern that the pedals maybe too close to the rider for comfort. However, by employing a minimalangle x between the fork and the stem, peddles 141 and 142 may bemaintained at a sufficient and comfortable distance from the riderwithout necessarily having to adjust the rider's position rearward, suchas might occur with an adjustable frame (although adjustable frames maybe used together with all embodiments of the invention). Thus, the frame700 may be configured to maintain a fixed, non-adjustable distancebetween the fork stem and the rear wheels. This can occur, for exampleby constructing the frame 700 from a fixed length, non-adjustable pieceof material.

In one embodiment, the shortest distance between the front wheel centerand the imaginary line of the fork axis is between 10 mm-30 mm. In oneembodiment, the shortest distance between the front wheel center and theimaginary line of the fork axis is between 15 mm-25 mm. In anotherembodiment the front wheel axis is designed to trail the stem axis inboth mode of operations the first and the second. The figure though isnon-limiting and alternatives may exist.

In one embodiment the width of the front wheel is at least three timesgreater than the minimum diameter of the fork's stem.

Embodiments of the invention may further include a rider handle,configured to turn the fork about a stem axis transverse to the frontwheel axis. As used herein, the term “rider handle” is used broadly torefer to any structure, regardless of shape, material, or size, that canbe grasped by a tricycle rider and used to turn the front wheel. Forexample the rider handle may be in the form of a handlebar, with acurved rod-like shape, or a straight rod-like shape. Alternatively, therider handle may be in the form of a steering wheel or other closed oropened loop structure capable of manipulation by a rider. The riderhandle may have a solid or open core. Like other parts of the tricycle,the rider handle may be made of any material or combination ofmaterials.

The rider handle may be configured to turn the fork via a mechanicalinterconnection with, for example, either the fork or the stem. Themechanical interconnection may be direct or may include intermediateparts through which forces may be transferred via the rider handle tothe front wheel.

By way of example only, a rider handle may include handlebar assembly200 illustrated in FIGS. 1 and 2. As illustrated in greater detail inFIG. 5 a, rider handle assembly 200 may include a handlebar 115, an arm201, and a coupling mechanism 202.

The rider handle, in a first mode, may be configured to be rotationallycoupled with the stem in a manner permitting a tricycle rider to exertforces on the rider handle and thereby turn the fork, and the riderhandle in the second mode, may be configured to be rotationallyuncoupled from the stem, preventing forces on the rider handle fromturning the fork. Rotational coupling and decoupling of the rider handlefrom the fork may be accomplished in numerous mechanical ways, and theinvention, in its broadest sense, is not limited to any particularmechanical interconnection. Rather, any manner in which the rider handlemay be coupled and uncoupled to the fork is considered to fall withinthe scope and spirit of the invention. Moreover, the location of acoupling decoupling mechanism is not necessarily critical to embodimentsof the invention. It may be located between a rider handle assembly anda stem, or it may be located between a stem and a fork.

Thus, by way of example only, the coupling mechanism 202 may, in a firstmode, permit mechanical interconnection between the rider handle and thefork such that when a tricycle rider applies a turning force to therider handle, the turning force is conveyed to the front wheel via thefork. In a second mode, the coupling mechanism 202 may decouple therider handle from the fork in a manner permitting the rider handle toturn freely without conveying turning forces to the fork. This may beaccomplished, for example, by permitting selective coupling anddecoupling of the rider handle from the stem. (e.g., selective couplingand decoupling of rider handle assembly 200 and stem 305).

Thus, the term “couple”, “coupling”, “coupling mechanism” and“rotational engageable” are meant herein to include any mechanicalengagement which transfers the rotation of one part to the other coupledpart, by causing it to rotate similarly.

When, in a first exemplary mode of operation the steering of tricycle800 is accomplished using rider handle assembly 200, i.e. the turning,e.g. left or right, of rider handle assembly 200 turns the fork 130which turns the front wheel 100, the rider may assume control ofsteering while simultaneously propelling the tricycle 800 using thepedals 141 and 142. If when the rider is in control in the first mode, aperson walking behind the tricycle tries to push the tricycle frombehind using parental handle 500, the rider may prevent the personwalking behind from assuming control. Thus the rider handle may bemechanically disconnected from the stem. When this occurs, the riderhandle may cease to function as a steering mechanism and may simplyfunction as support that the rider may grasp for balance or in order topermit a child to pretend to steer. In this circumstance, the riderhandle may lock in a stationary position rotationally disconnected fromthe fork and front wheel, or may rotate freely within a range of motionindependent of the fork and the front wheel.

There are many differing ways in which a handle assembly may berotatably coupled and decoupled from a fork or fork stem. The examplesprovided in this specification are not intended to limit the inventionto any particular example. Other coupling and decoupling mechanisms maybe used such as a detent, a pin, a screw connector, or any otherconnectors. One example, illustrated in FIG. 5 c involves an engageableand disengageable coupling. For example, a coupling member 204associated with the rider handle assembly 200 may include a surface thatselectively mates with an extension of the stem. As illustrated in FIG.5 c, for example, a shaped end 308 of stem 305 is selectively mateablewith a corresponding shaped slot 307 of coupling member 204. When theshaped end 308 is seated in slot 307, force exerted on the rider handleassembly 200 is capable of turning the stem 305, and consequently fork133 and wheel 100. When the shaped end 308 is decoupled from slot 307 ofcoupling member 204, the rider handle assembly 200 may be incapable ofturning the wheel 100.

The stem's top end 308 in this example, has an almost rectangular shape,although for most of its length the fork stem 305 is round. The opening307, depicted in silhouette since the opening 307 is hidden from thisview point, has a corresponding shape thereto. Hence, while beinginserted into the opening, the fork stem 305 is affixed, i.e. it cannotrotate, inside the second coupling member 204. Moreover, the almostrectangular shape is non-limiting and many other, non-round shapes canbe used for the purpose of affixing the fork stem 305 inside the secondcoupling member's opening 307.

As illustrated in FIG. 5 b, a knob 810, or any other manuallyactivatable release mechanism, which may be a part of the couplingmechanism 202, may be used for coupling the handle arm 201 to the fork'sstem 305. Specifically, and as described later in greater detail, whenknob 810 is lifted, decoupling occurs, and when it is moved downwardonto stem 305, coupling occurs. Thus, in a first mode, rider handleassembly 200 is rotationally engageable with the fork's stem 305 in amanner permitting a tricycle rider to exert forces on the rider handle200 and thereby turn the fork. On the other hand, the rider handle 200in the second mode, may be rotationally disengageable from the fork'sstem 305 for preventing forces on the handle from turning the fork.Examples of other structures that may be used to selectively couple ahandle to a stem include protruding spring-biased pins that can bedepressed to decouple and which can snap back into place to couple; orusing the pin 309 without part 810 for coupling and decoupling the ridehandle 200 to the stem 305, as described in relations to FIG. 7, etc. .. .

FIG. 5 b is a cross-sectional view of a part of the coupling mechanism202, according to one embodiment of the invention. The mechanism 202allows coupling of the handle arm 201 and the fork stem 305. Three mainmembers are depicted in the diagram: a first coupling member 203, asecond coupling member 204 and a grasping member 810 (or a knob). Thefirst coupling member 203 is statically coupled to the handle arm 201,thereinside. In the middle of the first coupling member 203 there is ashaft through which the fork stem 305 can be inserted. The secondcoupling member 204 is positioned inside the top end of the firstcoupling member 203, being slideable up and down. In the bottom of thesecond coupling member 204 there is an opening 307 into which the topend 308 of the fork stem 305 may fit. When the second coupling member204 is in its upper position, it is disengaged from the fork stem 305.When the second coupling member 204 slides down, the fork stem 305 isinserted into the opening 307, and a coupling is achieved between thesecond coupling member 204 and the fork stem 305, and hence also betweenthe steering arm 201 and the fork stem 305. In order to affix the forkstem 305 inside the second coupling member's 204 opening, the fork stem305 has a non-round shape in its top end and the opening has acorresponding shape thereto, as illustrated in a non-limiting way. Thegrasping member 810 is, on one hand, external to the handle arm's tube201 and on the other hand internal and connected to the second couplingmember 204, by a connecting element 309 such as a pin, a screw, or anyother element. Thus by sliding the grasping member 810 up and down, thesecond coupling member 204 also slides up and down as well. Moreover,the grasping member 810 as depicted in the diagram provides theindividual using it a better grip and easier control on the secondcoupling member's 204 position (whether up or down). However, in otherembodiments the grasping member 810 is redundant or not required, andthen, the connecting element 309 alone may be used as a third couplingmember, as described in relations to FIG. 7. The connecting element 309has been depicted as a single element, such as pin etc. connecting bothsides of the third coupling grasping member 810 via the handle arm 201and the second coupling member 204. This is not mandatory though and inother embodiments other solutions can be applied instead. For example,by having a third coupling member composed of two parts (e.g., a “rightpart” and a “left part”), a short pin can be coupled to each part, whilethe short pin can penetrate the steering arm and form the connectionwith the second coupling member, whereas, in another embodiment, the twoparts may be connected by a spring. In one embodiment second couplingmember 204 may be designed from two interconnecting parts each made froma different material.

In one embodiment, the coupling mechanism 202 may be in the front tube707 of the frame 700. In other embodiments, the coupling mechanism mayappear on top of the front tube 707.

FIG. 6 is a cross-sectional view of the handle arm 201 holding the firstcoupling member 203, according to one embodiment of the invention. Asdepicted in the diagram, the first coupling member 203 is held bygrasping elements 610, such as snaps, in the handle arm's tube 201. Inthe presently illustrated example, there are two snaps holding the firstcoupling element, one of each side, yet this in non-limiting and anyother number of snaps can be used, as long as the first coupling memberis affixed within the steering arm's tube. The shaft 306 is the shaft inwhich the fork stem may slide in. These figures though are non-limiting,and other coupling mechanisms may be used and other alternatives mayexist.

FIG. 7 is a cross-sectional side view of the second coupling member 204inside the first coupling member 203, according to one embodiment of theinvention. In the handle arm's tube 201 there are grooves 713. Throughthese grooves a guiding element 714, connected to the second couplingmember 204, can slide up and down, thus lifting and lowering,respectively, the second coupling member 204. The second coupling member204 should stay in a low, down position when coupled to the pivot, andin an upper, high position when disconnected therefrom, a lockingmechanism is described. According to one embodiment, this lockingmechanism comprises protrusions 716 in the groove 713. When the guidingelement crosses a protrusion 716, it is locked therebehind. In order toallow crossing of the guiding element, the protrusion should be made ofa flexible or resilient material. In addition, if the steering arm ismade of a non-flexible material, it is possible to attach theretoanother layer of a flexible material, either from the inside or from theoutside, forming the protrusion in this flexible layer. In the presentembodiment, the first coupling member 203, which is attached to thehandle tube 201 from the inside, can form this layer. Hence, asillustrated in the diagram, grooves are seen also in the first couplingmember 203, wherein the protrusions 716 are implemented therein. This isnon-limiting though and instead of using the first coupling member asthe flexible layer, other solutions may be provided as a dedicated pieceof flexible material which is attached to the handle arm's tube instead.Yet other embodiments may use other solutions, alternative to theprotrusions, such as using a screw as the guiding element, screwing itin the position where it needs to be locked.

In those cases when the coupling mechanism includes a knob, such aselement 810, as described with reference to FIG. 5 b, the guidingelement may form also the connecting element 309. Alternatively, theremay exist a connecting element 309, which is additional to the guidingelement. In one embodiment the guiding member alone may be the knob usedfor coupling and/or decoupling.

FIG. 8 illustrates the knob 810, according to one embodiment of theinvention. As was noted above, in one embodiment, the connecting element309 is able to slide up and down in the groove.

FIG. 9 a is a cross-sectional side view of the coupling mechanism in theuncoupled position. It can be seen, from looking at FIG. 9 a that thetop end of the fork stem 305 is free, that is, it is not inserted intothe opening 307 of the second coupling member 204. FIG. 9 b is across-sectional side view of the coupling mechanism in the coupledposition. In FIG. 9 b, illustrating the coupled position, the top end ofthe pivot is inserted into the opening 307. In each one of the positionsdescribed with reference to FIGS. 9 a and 9 b, the fork stem 305 isrotatably held in the first coupling member 203. In order to keep thefork stem 305 held in the first coupling member 203, the fork stem 305has an indentation 910. The indentation may include, for example, agroove that fully or partially circumscribes the stem 305, or it mayinclude a confined recess in the stem 305. A locking member 911 having aspring 912, clenching the pivot's indentation, may prevent it fromsliding out and releasing therefrom. Therefore, the locking member 911may prevent the fork stem 305 from releasing from the couplingmechanism.

FIG. 10 is a perspective view of the holding mechanism for engaging thefork stem 305, according to one embodiment of the invention. The lockingmember 911, in this case, has an oval opening 1010 through which thehead of fork stem 305 can pass, and one or more springs 912. The lockingmember 911 has a first side 1011 and a second side 1012. It is notedthough that the locking member is not necessarily rectangular and it maynot have definable sides. However, in order to explain the affixingmechanism, the embodiment illustrated is nearly rectangular in shape.When inserted into the handle tube, or into the first coupling member,the spring/springs 912 push the locking member 911 towards its 1011side, against the tube's wall. Upon inserting the pivot into the shaftof the first coupling member, the fork stem 305 reaches the lockingmember 911. Then, the top of the pivot's end pushes the lockingmechanism 911 towards its 1012 side. When the pivot's indentationreaches the locking mechanism 911, the spring/springs 912 are slightlyreleased and push the mechanism into the indentation, thus affixing thefork stem 305 in correspondence to the locking mechanism 911 and hencealso in correspondence with the first coupling member. The mechanismillustrated in FIG. 10 is non-limiting and many other one-time lockingmechanisms known per se may be used alternatively, as applicable.

Embodiments of the invention may also include at least rotationrestrictor, for preventing the front wheel from turning to a positionwhere the front wheel axis leads the fork axis, and for maintaining thefront wheel axis in a position trailing the fork axis both when thetricycle is propelled by a tricycle rider in the first mode and when thetricycle is pushed from behind in the second mode. As used herein, “arotation restrictor for preventing” includes any structure capable ofrestricting the rotational movement of the front wheel, regardless ofwhether the restrictor completely prevents rotation past a certainpoint, or whether the restrictor only prevents rotation past a certainpoint when forces exerted are below a threshold (e.g., the restrictormay exert a bias force that may be overcome by an opposing force greaterthan the bias force.) In either instance, a rotation restrictorconsistent with embodiments of the invention may be used to maintain thefront wheel in an orientation where the front wheel axis trails the forkaxis in both a first rider steering mode and a second parental controlmode.

There are a myriad of ways in which rotation between two parts may berestricted. The invention, in its broadest sense, is not limited to anyparticular restriction mechanism. Thus, by way of example only, FIG. 11is a diagram of the frontal part of the main frame 700 and the head tube707, from a bottom view, without the front wheel assembly and withoutthe rider handle assembly 200, according to an embodiment of theinvention. The head tube 707, described in relations to FIGS. 1 and 2,may include a rotation restrictor in the form of stop 710, forpreventing the front wheel from turning to a position where the wheelaxis leads the fork axis. Although, for the sake of brevity, anembodiment of the stop is brought forth, other embodiments of a stop arepossible. The stop 710 may have a number of protrusions, such as theprotrusion 711, protrusion 712, protrusion 713, and protrusion 714. Inone embodiment only two protrusions are needed, such as protrusions 711and 713. In another embodiment only one protrusion may be needed. Theseprotrusions may be used for limiting the swivel angle of the frontwheel.

FIG. 12 is a schematic diagram of the mud guard 301, according to anembodiment of the invention. The mud guard 301, as described inrelations to FIG. 1, may have at least one protrusion, two protrusionssuch as protrusions 377 and 378, or any number of protrusion. In thisexample, as depicted in the diagrams, the protrusion 377 of mud guard301 is meant to fit between the protrusions 712 and 713 of stop 710,whereas protrusion 378 of mud guard 301 is meant to fit between theprotrusions 711 and 714. The limit of the protrusions of the mud guard301 between the protrusions of the stop 710 allows on one hand theturning of the mud guard in a preset angle, hence the turning of thefront wheel in a preset angel, and on the other hand prevents the mudguard from turning in a wider angle thus maintaining the wheel axis in aposition trailing the fork axis both when the handle is in the firstmode and when the handle is in the second mode. In one embodiment theturning angle between the protrusions of the stop 710 may be between 80°and 100°. In another embodiment, the turning angle between theprotrusions of the stop 710 may be around 90°. In one embodiment theturning angle between the protrusions of the stop 710 may be less than180°. In one embodiment a protrusion 723 may be added in order toprevent the assembling of the mud guard incorrectly. In some embodimentsthe stop may be designed differently and located in other parts of thetricycle as long as it prevents the front wheel from turning to aposition where the wheel axis leads the fork axis. For example the stopmay be located in the stem of the fork, in the mud guard, in the handlearm, or in any place externally or internally to the tricycle. By way offurther example, one or more stops may be located on the fork and/or thestem, to restrict relative motion therebetween. Alternatively, one ormore stops could be located on the stem and/or the handle to restrictrelative motion therebetween. Moreover, one or more stops might belocated on a fixed portion of the tricycle, such as the frame or a fixedcomponent connected to the frame, to restrict motion of any one of thefork, the stem, the handle, or a component connected to any one of theforegoing. Thus, the exemplary illustrations in the figures areconceptual only and are not intended to limit the invention to aparticular configuration of rotation restriction.

In one embodiment the rider handle angle is restricted as well due tosafety considerations, protecting the body of the rider from being hitby the rider handle. In one embodiment the turning angle of the riderhandle may be between 80° and 100°. In one embodiment the turning angleof the rider handle may be around 90°. In one embodiment the turningangle of the rider handle may be between 20° and 170°.

With such configurations, the front wheel of a tricycle may always bemaintained in a position with the stem axis leading the wheel axis,regardless of whether the tricycle is propelled by a rider or pushedfrom behind. Thus, in some embodiments, all a parent need do to takeover steering control is to disengage the rider handle from the frontwheel. The front wheel, in this example, need not be rotated to a newposition, since the wheel position may remain the same regardless of themode of operation. Similarly, if a parent is pushing the tricycle, anddesires to turn steering control over to the rider, all the parent needto do, in this embodiment, is to couple the rider handle to the frontwheel. Since rider steering control may be achieved with the stem axisleading the wheel axis, the parent need not re-orient the front wheel.

Depending on the embodiment, the tricycle may provide an option ofchanging pedal position between modes of operation. In one embodiment afootrest 300 (see FIG. 2) may be connected to the main frame 700 forallowing the rider to rest his feet on the footrest 300 while thetricycle 810 is being pushed from behind. In one embodiment the footrest300 is foldable, and it may be folded backwards under the chair 600 orit may be folded in any other way. In one embodiment the pedal rod 140propelling factor may be disengaged from the rotating factor of thewheel 102, effectively allowing the pedals to stay static while thetricycle 810 is being pushed. The method for engaging and disengagingthe pedal rod propelling factor and the rotating factor of the wheel isknown in the art. In the second mode of operation the rider handle 200may be uncoupled from the fork 130, effectively allowing an individualto push the tricycle 810 from behind and steer it using the parentalhandle 500 while the rider sits on the chair 600, rests his feet on thefoot rest 300 and rests his hands on the rider handle 200. Meaning thatin this second mode of operation, the steering of the tricycle 810 doesnot have to interfere with the rider's hands holding the rider handle200. Nevertheless, the tricycle 810 may be changed to the first mode ofoperation by coupling the fork 130 with the rider handle 200, optionallydetaching the parental handle 500, optionally folding the footrest 300,and optionally reengaging the pedal rod 140 to the front wheel 102. Thusin the first mode of operation the rider can propel the tricycle 810 byhimself using the pedal rod 140 and steer the tricycle 810 by himselfusing rider handle 200.

While some embodiments of the invention have been described by way ofillustration, it will be apparent that the invention can be carried intopractice with many modifications, variations and adaptations, and withthe use of numerous equivalents or alternative solutions that are withinthe scope of persons skilled in the art, without departing from theinvention or exceeding the scope of claims.

1. A tricycle operable between a first mode of operation steerable by atricycle rider, and a second mode of operation steerable by anindividual pushing the tricycle, the tricycle comprising: a frame; apair of rear wheels for rotatable connection to the frame; a front wheelhaving opposing sides and a front wheel axis; a pair of pedals, eachpedal configured to rotate the front wheel; a fork having at least oneblade configured to support the front wheel in a manner permitting thefront wheel to rotate about the front wheel axis; a stem extending fromthe fork and being rotatably connectable to the frame; a rider handle,configured to turn the fork about a stem axis transverse to the frontwheel axis, the rider handle, in the first mode, being configured to berotationally coupled with the stem in a manner permitting a tricyclerider to exert forces on the rider handle and thereby turn the fork, andthe rider handle in the second mode, being configured to be rotationallyuncoupled from the stem, preventing forces on the rider handle fromturning the fork; and at least one rotation restrictor, for preventingthe front wheel from turning to a position where the front wheel axisleads the stem axis, and for maintaining the front wheel axis in aposition trailing the stem axis both when the tricycle is propelled by atricycle rider in the first mode and when the tricycle is pushed frombehind in the second mode.
 2. The tricycle of claim 1, wherein the forkincludes two blades configured to rotatably support the front wheeltherebetween.
 3. The tricycle of claim 1, wherein the handle isconfigured to be uncoupled from the stem via a manually activatablerelease mechanism.
 4. The tricycle of claim 3, wherein the handle isconfigured to be coupled to the stem via a snap-in-place mechanism. 5.The tricycle of claim 1, wherein the rotation restrictor is configuredto permit the front wheel to turn less than 180 degrees, whilemaintaining the front wheel in a position such that the wheel axistrails the stem axis.
 6. The tricycle of claim 1, wherein the rotationrestrictor is configured to permit the front wheel to turn less than 100degrees, while maintaining the front wheel in a position such that thewheel axis trails the stem axis.
 7. The tricycle of claim 1, furthercomprising a coupling mechanism associated with the stem, for permittingan operator to selectively couple and uncouple a rotational connectionbetween the handle and the stem.
 8. The tricycle of claim 7, wherein thecoupling mechanism is configured such that in the second mode, the riderhandle is freely rotatable independent of the stem, and in the firstmode the rider handle is locked to the stem for rotation with the stem.9. The tricycle of claim 1, wherein the front wheel has a diameter and awidth, wherein the stem has a minimum diameter, and wherein the width ofthe front wheel is at least three times greater than the minimumdiameter of the stem.
 10. The tricycle of claim 1, wherein the stemincludes a steel tube that has a minimum diameter that is at least fourtimes smaller than a width of the front wheel.
 11. The tricycle of claim1, where the stem extends from the fork at an angle of between about 165degrees and 179 degrees.
 12. The tricycle of claim 1, wherein the frameis configured to maintain a fixed, non-adjustable distance between thefork stem and the rear wheels.
 13. The tricycle of claim 5, wherein theframe is configured to maintain a fixed, non-adjustable distance betweenthe fork stem and the rear wheels.
 14. The tricycle of claim 1 whereinan offset distance between a stem axis and a front wheel axis is between15 mm and 40 mm, an angle between the stem and the fork is between about7 and 10 degrees, and a minimum diameter of the stem is at least threetimes less than a width of the front wheel.
 15. The tricycle of claim 1,further including a parental handle extending from a rear portion of thetricycle and permitting the tricycle to be pushed and steered frombehind.
 16. A tricycle operable between a first mode of operationsteerable by a tricycle rider, and a second mode of operation steerableby an individual pushing the tricycle, the tricycle comprising: a forkhaving at least one blade configured to support a front wheel in amanner permitting the front wheel to rotate about a front wheel axis; astem extending from the fork; a handle configured to turn the forkaround a stem axis transverse to the front wheel axis, the handle, inthe first mode, being rotationally coupled with the stem in a mannerpermitting a tricycle rider to exert forces on the handle and therebyturn the fork, and the handle in the second mode, being rotationallyuncoupled from the stem, preventing forces on the handle from turningthe fork; and a rotation restrictor, for preventing the front wheel fromturning to a position where the wheel axis leads the stem axis, and formaintaining the wheel axis in a position trailing the stem axis bothwhen the handle is in the first mode and when the handle is in thesecond mode.
 17. The tricycle of claim 16 wherein an offset distancebetween a stem axis and a front wheel axis is between 15 mm and 40 mm,an angle between the stem and the fork is between about 7 and 10degrees, and a minimum diameter of the stem is at least three times lessthan a width of the front wheel.
 18. The tricycle of claim 16, where thestem extends from the fork at an angle of between about 170 degrees and179 degrees.
 19. The tricycle of claim 16, wherein the stem includes asteel tube that has a minimum diameter that is at least four timessmaller than a width of the front wheel.